The present invention relates to linear recliner assemblies and more particularly to a linear recliner assembly having a fixed pawl.
Occupant safety and comfort are paramount concerns for automobile manufacturers. In particular, vehicle seating systems are a significant focus for improved comfort and safety. Conventional vehicle seating systems include reclining seats that enable comfort adjustment by a vehicle occupant.
In reclining seats, a recliner assembly is mounted to a long lever arm, namely the seat back, against which various forces are applied. The recliner assembly in a vehicle seat is quite small when compared with the length of a seatback, and vehicle vibration or movement of an occupant may impose various forces upon that lever arm during use. Because these forces are applied along such a lengthy lever arm, they can impose a large moment about the recliner assembly""s pivot point potentially overcoming the capability of the assembly to anchor the seatback.
In addition, any imperfections in the components of the recliner assembly, such as play or backlash between the engaging teeth or tolerances in the assembly components, may allow the seatback to move a miniscule amount even when the assembly is locked. These small excursions are magnified by the length of the lever arm and become noticeable at the upper end of the seatback. For example, the seatback of an unoccupied seat may tend to oscillate when the vehicle encounters rough road conditions. This magnified play in a recliner assembly has been termed xe2x80x9cchuckingxe2x80x9d and refers to any imperfection or play in the assembly components that allows movement of the lever arm or seatback while the assembly is in a locked condition.
Therefore, it is desirable in the industry to provide a recliner assembly that significantly reduces or eliminates chucking of a seat assembly. It is further desirable that such a recliner assembly be sufficiently strong, providing adequate occupant protection in the event of an accident.
It is also desirable in the industry to reduce the overall complexity of traditional reclining assemblies while maintaining operation and safety standards. In this manner, overall cost is reduced through implementation of fewer components and improved manufacturability. Additionally, a weight savings can be achieved through the utilization of fewer components in the reclining assembly.
Accordingly, a simplified linear recliner assembly according to the present invention overcomes the above described deficiencies of present linear recliner assemblies. Specifically, the linear recliner assembly of the present invention includes fewer components and a less complex overall design than previous linear recliner assemblies.
The linear recliner assembly of the present invention includes a housing, a recliner rod slidably supported within the housing, a pawl supported by the housing, and a cam rotatably supported by the housing. The cam has a cam surface that slidably interfaces the recliner rod. The cam is rotatable for selectively engaging the recliner rod with the pawl such that the recliner rod is prohibited from linear movement when engaged with the pawl. Preferably, the cam is biased in a first direction of rotation to force the recliner rod into engagement with the pawl. The cam is rotatable against the biasing force to disengage the recliner rod from the pawl for linear adjustment of the recliner rod relative to the housing.
Some advantages of the linear recliner assembly of the present invention include improvements in cost, weight and manufacturability of the linear recliner assembly.
A further advantage of the present invention is a simple, compact construction that reduces tolerance stack-up that would otherwise result in significant seat back chucking.
Additionally, packaging and trim of the overall seat assembly is more easily achieved because the recliner assembly""s moving parts are internal to the compact housing.